CHATTANOOGA (AP) — The newest reactor at the Watts Bar Nuclear Plant in Spring City has begun generating electricity.

The Chattanooga Times Free-Press reports that the Tennessee Valley Authority synced the reactor to the grid on Friday.

Operators have begun an initial test run of generation equipment to collect data and ensure the equipment is prepared for continuous operation in the summer.

TVA Chief Nuclear Officer Joe Grimes called the test run a major step in fully integrating the reactor as the seventh operating unit in the nuclear fleet.

The next step is a full-plant testing of systems and controls at increasing reactor power levels.

The plant is expected to supply power to roughly 1.3 million homes.